c# - DESERIALIZE 上的 InvalidoperationException

Question

我想将一个 XML 反序列化为一个对象，但不断收到以下异常

System.InvalidOperationException: There is an error in XML document (0, 0).     ---> System.Xml.XmlException: Root element is missing.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
at System.Xml.XmlTextReaderImpl.Read()
at System.Xml.XmlTextReader.Read()
at System.Xml.XmlReader.MoveToContent()
at   Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderBAObjectSchema.Read18_BAObjectSchema()
   --- End of inner exception stack trace ---
   at System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events)
   at System.Xml.Serialization.XmlSerializer.Deserialize(TextReader textReader)
   at Siemens.BASys.BAObjectCreator.SchemaHandler.Deserialize[T](String path, Boolean throwException) in ....\SchemaHandler.cs:line 34

我正在使用的代码

` public static T Deserialize<T>(string path, bool throwException)
    {

        T root = default(T);
        try
        {
            using (FileStream fs = new FileStream(path, FileMode.Open))
            {
                using (TextReader reader = new StreamReader(fs))
                {
                    //XmlSerializer serializer = new XmlSerializer(typeof(T));
                    XmlSerializer serializer = new XmlSerializer(typeof(T));
                    root = (T)serializer.Deserialize(reader);
                }

            }
        }
        catch (Exception e)
        {
            System.Diagnostics.Debug.WriteLine(e.ToString());
        }
        return root;
    }`

我使用的 XML 看起来是正确的，但不确定为什么会出现错误

以下是XML的示例部分

<?xml version="1.0" encoding="utf-8"?>
<ObjectSchema>
  <Controllers>



  </Controllers>
</ObjectSchema>

任何帮助将不胜感激

谢谢

Answer 1

代码和 XML 都没有问题。这是因为 StreamReader。一旦到达 EOF，当 XMLSerializer 尝试从状态为 EOF 的同一个 Stream 中读取时，流是仅向前模式的读取器 i.e. 游标位于文件末尾并且没有根标记。

而不是使用允许多次阅读的 TextReader 用户 XMLTextReader。

using (FileStream fs = new FileStream(path, FileMode.Open))
 {
    using (XmlReader reader = new XmlTextReader(fs))
      {
         XmlSerializer serializer = new XmlSerializer(typeof(T));
         root = (T)serializer.Deserialize(reader);
      }

 }